Process for the continuous preparation of 3-halopropylorganosilanes

Abstract

A process for the continuous preparation of 3-halopropylorganosilanes of the general structure R b H 3-a-b X a SiCH 2 CH 2 CH 2 Y  (III), where: R is CH 3 , C 2 H 5 , C 3 H 7 , OCH 3 , OC 2 H 5 or OC 3 H 7 , X is F, Cl, Br or I, Y is F, Cl, Br or I, and a and b are each one of the numbers 0, 1, 2 or 3 and the sum a+b is 1, 2 or 3, comprising reacting, as starting materials, an allyl halide with a silane carrying at least one H atom, wherein the starting materials are present in stoichiometric amounts or one of the starting materials is present in substoichiometric amounts, wherein the reaction carried out is a partial reaction of from 10% to 80%, on a molar basis, of the starting materials, based on either material, when both are present in stoichiometric amounts, or based on the substoichiometric material.

What is claimed as new and desired to be secured by Letters Patent of the United States is:  
     
       1. A process for the continuous preparation of 3-halopropylorganosilanes of the general structure 
       
         
           R b H 3-a-b X a SiCH 2 CH 2 CH 2 Y  (III),  
         
       
       where: 
       R is CH 3 , C 2 H 5 , C 3 H 7 , OCH 3 , OC 2 H 5  or OC 3 H 7 ,  
       X is F, Cl, Br or I,  
       Y is F, Cl, Br or I, and  
       a and b are each one of the numbers 0, 1, 2 or 3 and the sum a+b is 1, 2 or 3, comprising reacting, as starting materials, an allyl halide with a silane carrying at least one H atom,  
       wherein the starting materials are present in stoichiometric amounts or one of the starting materials is present in substoichiometric amounts,  
       wherein the reaction carried out is a partial reaction of from 10% to 80%, on a molar basis, of the starting materials, based on either material, when both are present in stoichiometric amounts, or based on the substoichiometric material.  
     
     
       2. The process as claimed in claim  1 , wherein the reaction carried out is a partial reaction of from 30% to 60%, on a molar basis, of the starting materials, based on either material, when both are present in stoichiometric amounts, or based on the substoichiometric material. 
     
     
       3. The process as claimed in claim  1 , wherein propene formed as a by-product is separated. 
     
     
       4. The process as claimed in claim  1 , wherein the molar ratio of silane to allyl halide is between 0.5 and 1.5. 
     
     
       5. The process as claimed in claim  4 , wherein the molar ratio of silane to allyl halide is between 0.5 and 1. 
     
     
       6. The process as claimed in claim  1 , wherein unreacted starting materials are separated from a product mixture and are recycled into the reaction. 
     
     
       7. The process as claimed in claim  1 , wherein the reaction is performed by heterogeneous catalysis. 
     
     
       8. The process as claimed in claim  1 , wherein the reaction is performed in the liquid phase at a temperature of between 60° C. and 160° C. 
     
     
       9. The process as claimed in claim  8 , wherein the reaction is performed in the liquid phase at a temperature of between 80° C. and 140° C. 
     
     
       10. The process as claimed in claim  1 , additionally comprising presetting the reaction temperature and/or the residence time of the reaction mixture in the reactor. 
     
     
       11. The process as claimed in claim  1 , wherein the 3-halopropylorganosilane is 3-chloropropyltrichlorosilane and the silane is trichlorosilane, the reaction is carried out at a temperature of between 60° C. and 160° C. and a residence time of the reaction mixture in the reactor of between 1 min and 500 min. 
     
     
       12. The process as claimed in claim  1 , wherein the 3-halopropylorganosilane is 3-chloropropyl-methyldichlorosilane and the silane is methyl-dichlorosilane, the reaction is carried out at a temperature of between 60° C. and 160° C. and a residence time of the reaction mixture in the reactor of between 1 min and 500 min.